This work reveals that the anisotropic layer Ir₂Cl₂O₂ exhibits high TE performance, which confirms that it is feasible to screen excellent TE materials via high-throughput calculations.

Alpha-1 antitrypsin (AAT) deficiency–related emphysema is the fourth leading indication for lung transplant. Chymotrypsin-like elastase 1 (Cela1) is a digestive protease that is expressed during lung development in association with regions of elastin remodeling, exhibits stretch-dependent expression during lung regeneration, and binds lung elastin in a stretch-dependent manner. AAT covalently neutralizes Cela1 in vitro. We sought to determine the role of Cela1 in postnatal lung physiology, whether it interacted with AAT in vivo, and to detect any effects it may have in the context of AAT deficiency. The lungs of Cela1 −/− mice had aberrant lung elastin structure and higher elastance as assessed with the flexiVent system. On the basis of in situ zymography with ex vivo lung stretch, Cela1 was solely responsible for stretch-inducible lung elastase activity. By mass spectrometry, Cela1 degraded mature elastin similarly to pancreatic elastase. Cela1 promoter and protein sequences were phylogenetically distinct in the placental mammal lineage, suggesting an adaptive role for lung-expressed Cela1 in this clade. A 6-week antisense oligonucleotide mouse model of AAT deficiency resulted in emphysema with increased Cela1 mRNA and reduction of approximately 70 kD Cela1, consistent with covalent binding of Cela1 by AAT. Cela1 −/− mice were completely protected against emphysema in this model. Cela1 was increased in human AAT-deficient emphysema. Cela1 is important in physiologic and pathologic stretch-dependent remodeling processes in the postnatal lung. AAT is an important regulator of this process. Our findings provide proof of concept for the development of anti-Cela1 therapies to prevent and/or treat AAT-deficient emphysema.

In this paper, the thermoelectric properties of p-type and n-type GeSe are studied systematically by using first principles and Boltzmann transport theory. The calculation includes electronic structure, electron relaxation time, lattice thermal conductivity and thermoelectric transport properties. The results show that GeSe is an indirect band gap semiconductor with band gap 1.34 eV. Though p-type GeSe has a high density of states near Fermi level, the electronic conductivity is relative low because there is no carrier transport pathway along the a -axis direction. For n-type GeSe, a charge density channel is formed near conduction band minimum, which improves the electrical conductivity of n-type GeSe along the a -axis direction. At 700 K, the optimal ZT value reaches 2.5 at 4 × 10 ¹⁹ cm ⁻³ for n-type GeSe, while that is 0.6 at 1 × 10 ²⁰ cm ⁻³ for p-type GeSe. The results show n-type GeSe has better thermoelectric properties than p-type GeSe, indicating that n-type GeSe is a promising thermoelectric material in middle temperature.

The electronic, vibrational and thermoelectric transport characteristics of AgInTe ₂ and AgGaTe ₂ with chalcopyrite structure have been investigated. The electronic structures are calculated using the density-functional theory within the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof functional considering the Hubbard-U exchange correlation. The band-gaps of AgInTe ₂ and AgGaTe ₂ are much larger than previous standard GGA functional results and agree well with the existing experimental data. The effective mass of the hole and the shape of density of states near the edge of the valence band indicate AgInTe ₂ and AgGaTe ₂ are considerable p-type thermoelectric materials. An analysis of lattice dynamics shows the low thermal conductivities of AgInTe ₂ and AgGaTe ₂ . The thermoelectric transport properties' dependence on carrier concentration for p-type AgInTe ₂ and AgGaTe ₂ in a wide range of temperatures has been studied in detail. The results show that p-type AgInTe ₂ and AgGaTe ₂ at 800 K can achieve the merit values of 0.91 and 1.38 at about 2.12 × 10 ²⁰ cm ⁻³ and 1.97 × 10 ²⁰ cm ⁻³ carrier concentrations, respectively. This indicates p-type AgGaTe ₂ is a potential thermoelectric material at high temperature.

The geometry structures, vibrational, electronic, and thermoelectric properties of bilayer GeSe, bilayer SnSe, and van der Waals (vdW) heterostructure GeSe/SnSe are investigated by combining the first-principles calculations and semiclassical Boltzmann transport theory. The dynamical stability of the considered structures are discussed with phonon dispersion. The phonon spectra indicate that the bilayer SnSe is a dynamically unstable structure, while the bilayer GeSe and vdW heterostructure GeSe/SnSe are stable. Then, the electronic structures for the bilayer GeSe and vdW heterostructure GeSe/SnSe are calculated with HSE06 functional. The results of electronic structures show that the bilayer GeSe and vdW heterostructure GeSe/SnSe are indirect band gap semiconductors with band gaps of 1.23 eV and 1.07 eV, respectively. The thermoelectric properties, including electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, and figure of merit (ZT) are calculated with semiclassical Boltzmann transport equations (BTE). The results show that the n-type bilayer GeSe is a promising thermoelectric material.

To explore the structural, vibrational, and thermodynamic properties of the chalcopyrite-type compound AgGaS₂ under pressure, we applied hydrostatic pressure to the relaxed compound based on the first principles calculation and quasi-harmonic approximation. The structural parameters, including lattice constants and bond lengths decrease monotonically with the increasing pressure. The phonon dispersion curves under various pressures reveal the structural phase transition of chalcopyrite-type compound AgGaS₂ at about 4 GPa. The intrinsic mechanism of thermal conductivity for the chalcopyrite-type compound AgGaS₂ has been shown with phonon anharmonicity. The frequencies of the optical phonons at the center point Γ of the first Brillouin zone were calculated with the longitudinal optical–transverse optical (LO–TO) splitting mode. The dependence of the frequencies of the optical phonons on the pressure provides the information for the Raman spectroscopic study under high pressure. The pressure dependence of the Grüneisen parameters indicates that the instability of chalcopyrite-type compound AgGaS₂ is associated with the softening of the acoustic phonon modes at around the center point Γ. The thermal conductivity for chalcopyrite-type compound AgGaS₂ could be reduced by applying external pressure. The various thermodynamic properties, such as the Helmholtz free energy, entropy, and heat capacity, at different temperatures and pressures were discussed and analyzed based on the phonon properties.